One billion people on the planet are struggling with extreme poverty according to Jeffrey D. Sachs, director of The Earth Institute at Columbia University. In this March 31 lecture, Sachs discusses his new book, The End of Poverty: Economic Possibilities for Our Time, which explores the challenge of global poverty. Sachs also shares accounts of his recent visits to Africa and offers practical solutions to the challenge of global poverty, which he contends can be eliminated by 2025.